var express = require('express');
var router = express.Router();
const { Course,Category,Chapter,User } = require('../models');
const { success, failure } = require('../utils/responses');

/* 
*  查询课程列表
*/
router.get('/', async function (req, res, next) {
    try {
        const query = req.query;
        // 页和每页现实几条数据
        const currentPage = Math.abs(Number(query.currentPage)) || 1;
        const pageSize = Math.abs(Number(query.pageSize)) || 10;
        const offset = (currentPage - 1) * pageSize;

        if (!query.categoryId) {
            throw new Error('获取课程列表失败，分类ID不能为空')
        }

        const condition = {
            attributes: { exclude: ['CategoryId', 'UserId', 'content'] },
            where: {categoryId: query.categoryId},
            order: [['id', 'DESC']],
            offset: offset,
            limit: pageSize
        }
        
        const { count, rows } = await Course.findAndCountAll(condition);
        success(
            res,
            '查询课程列表成功',
            {
                course: rows,
                pagination: {
                    total: count,
                    currentPage,
                    pageSize
                }
            }
        )
    } catch (error) {
        failure(res, error)
    }
});


// 查询课程详情
router.get('/:id', async function (req, res, next) {
    try {
        const { id } = req.params;
        const condition = {
            attributes: { exclude: ['CategoryId', 'UserId'] },
            include: [
                { model: Category, as: 'category', attributes: ['id', 'name'] },
                {
                    model: Chapter, as: 'chapters',
                    attributes: ['id', 'title', 'rank','createdAt'],
                    order: [['rank', 'ASC'], ['id', 'DESC']]
                },
                {
                    model: User, as: 'user',
                    attributes: ['id', 'username', 'nickname', 'avatar', 'company']
                },
            ]
        };

        const course = await Course.findByPk(id, condition);
        if (!course) {
            throw new NotFoundError(`ID: ${id}的课程未找到`)
        }
        success(
            res,
            '查询课程成功',
            {course}
        )

    } catch (error) {
        failure(res, error)
    }
});


module.exports = router;
